Dick Lugar is going to lose. Did he have to?

Indiana Republican Sen. Dick Lugar will almost certainly lose his bid for a seventh term Tuesday at the hands of state Treasurer Richard Mourdock.

View Photo Gallery: Few incumbent senators have lost bids for their parties’ nomination over the last 60 years, making Sen. Richard Lugar’s (R-Ind.) potential loss on Tuesday all the more newsworthy. We look at Lugar and nine senators whose losses surprised us the most.

There is considerably more disagreement about whether Lugar’s loss was inevitable or whether he could have avoided the fate almost certainly headed his way today. And both arguments have some merit.

Mourdock, who was elected to his current post in 2006 and re-elected in 2010, announced his primary challenge to Lugar way back in February 2011. That announcement came less than a year removed from the defeats of Republican Sens. Bob Bennett (Utah) and Lisa Murkowski (Alaska) — both of whom fell to intra-party challengers running to their ideological right and casting the incumbents as defenders of an unacceptable political status quo. (Murkowski wound up holding her seat through a write-in campaign.)

Given that, it’s impossible to cast Lugar as surprised by the challenge that Mourdock presented him. “The only people who seem to be surprised about any of this were the Lugar people themselves; no one else is surprised at this, because everyone else got the message from last cycle,” said one national Republican operative.

At the start of 2011, Lugar met with senior party strategists who walked him through the mistakes made by the likes of Murkowski and Bennett — and emphasized how he too was vulnerable unless he took a far more aggressive approach to the possibility of a primary fight. Lugar chose not to heed those warnings.

Instead, the senator seemed to believe — wrongly — that his situation was unique, that his connection to voters in the Hoosier State went deeper and was, therefore, tougher to break than those of his losing colleagues.

It’s somewhat understandable why he might feel that way. Lugar hadn’t won reelection with less than 67 percent of the vote since 1982. And, prior to winning his Senate seat in 1976, he served as mayor of Indianapolis for seven years.

And his opponent, Mourdock, had lost five previous races — including three bids for Congress, and struggled to raise any considerable amount of money for his campaign. (At the beginning of 2012, Lugar had over $4 million in the bank, while Mourdock had just $362,000.)

What Lugar should have done, according to traditional campaign tactics, was to use that massive financial advantage to kill Mourdock’s candidacy in the crib, to define the challenger before he (or any conservative-aligned national groups supporting Mourdock) had the chance to tell his story in a more positive light.

(Perhaps the best example of that strategy came in 2010, when Arizona Sen. John McCain used his financial edge to destroy the candidacy of former Rep. J.D. Hayworth before the latter even hit the television airwaves.)

It’s not that simple, according to Lugar allies who acknowledge he is likely to come up short against Mourdock in the primary.

“Conventional wisdom is that he should have gone nuclear early, but that would have killed him out of the gate,” said one Republican strategist who has worked in the state and is sympathetic to the incumbent. “Indiana would simply not have accepted that from him.”

The other problem for Lugar, according to the source, was that there was never a clean hit available on Mourdock that matched the incumbent’s support for the Troubled Asset Relief Program (TARP), his votes on judges, nagging residency questions, and, yes, the friendliness between him and President Obama. (Lugar has been floated as a possible Defense Secretary in the Obama Administration.)

The only path to victory available for Lugar seems to have been one that he was unwilling or unable — depending on how you view him and his career — to implement, including changing his voting record and his rhetoric on the campaign trail..

“He was never willing to become what he is not,” said one GOP strategist favorably inclined to Lugar. “He is far too thoughtful a man to boil things down to tea party-acceptable soundbites, or simply laser-focus his rhetoric only on economic issues despite any number of requests to do so.”

In the end, Dick Lugar decided to be Dick Lugar. And that decision almost certainly will cost him his Senate career.

The former Pennsylvania senator, who dropped out of the GOP presidential race nearly a month ago, wrote on his website that he will back the former Massachusetts governor.

Santorum said he wanted to meet with Romney face-to-face before making the endorsement.

“Above all else, we both agree that President Obama must be defeated. The task will not be easy. It will require all hands on deck if our nominee is to be victorious,” Santorum wrote on his website. “Gov. Romney will be that nominee, and he has my endorsement and support to win this the most critical election of our lifetime.”

DSCC reserves time in three states: The Democratic Senatorial Campaign Committee has reserved ad time in three key states, the first indication of which states it sees as the most important to the 2012 campaign.

The DSCC has reserved a total of $14.1 million in ad time in Missouri, Montana and Virginia, including $7.4 million in the last state, The Fix has confirmed.

All three seats, notably, are Democratic-held seats — a reflection of the fact that the majority party is playing more defense than offense this year. That’s no surprise.

Also, keep in mind that reserving time doesn’t lock the committee into actually buying ads, and it can always change its mind. The National Republican Senatorial Committee previously reserved $25 million worth of ad space in six states, including these three states.

That said, Virginia and Montana are sure-fire toss-ups this fall. Missouri, in the other hand, looks like a tough hold, and if the DSCC spends money there, it’s because it thinks it can hang on. We shall see.

Democratic super PAC buys time in Arizona special: House Majority PAC, the top super PAC aimed at helping Democrats win the House, is going up with $340,000 worth of ads in the special election to replace Rep. Gabrielle Giffords (D-Ariz.), according to a PAC aide.

The ad buy is for three weeks and will attempt to use Republican nominee Jesse Kelly’s words against him.

The ad buy is further evidence that, despite goodwill for former Giffords aide Ron Barber, the conservative-leaning seat is no sure thing for the party. Both major party committees have also gone up with ads in the Tucson-based district.

Four states hold elections: Voters in four states head to the polls today, with Indiana, North Carolina, and West Virginia holding state and presidential primaries, and Wisconsin Democrats holding a primary to determine who will run in next month’s recall against Gov. Scott Walker (R).

Stay tuned to The Fix this morning for our preview of all the big contests.

Fixbits:

Some GLBT donors are reportedly withholding donations from Obama’s super PAC due to his refusal to sign an executive order banning sexual discrimination by federal contractors.

Nebraska state Sen. Deb Fischer (R) releases a poll showing her surging to second place — ahead of state Treasurer Don Stenberg — in the Nebraska GOP Senate primary, and within the margin of error against state Attorney General Jon Bruning.

Arizona state House Speaker Andy Tobin (R) has opted against running in a primary with Rep. Paul Gosar and Pinal County Sheriff Paul Babeu.